At our dd's 6 month check up, she was 12 pounds 3 ounces, 23.5 inches and ped was fine with it. I was worried she would make me start supplementing but she said I was doing a great job. She was born at exactly 38 weeks and weighed 5 pounds. She was 4 pounds 13 ounces when we left the hospital, 4 pounds 14 ounces at her 1 week check up. At one month she was 6 pounds 9 ounces, 2 months 8 pounds 2 ounces and 4 months 11 pounds 2 ounces.

I think you're doing a great job and if if we're me, I'd definitely find a new doc!